Glue classes proposal 0.9

Joseph D. Darcy Joe.Darcy at Sun.COM
Sat Mar 21 19:28:35 PDT 2009


 From this proposal, I do not understand what you are trying to propose.

-Joe

Marek Kozieł wrote:
> AUTHOR: Lasu aka Marek Kozieł
>
> OVERVIEW
>
> FEATURE SUMMARY:
> Glue classes allow to link utils direct with objects.
>
> MAJOR ADVANTAGE:
> + Forgotten functionality can be not such big deal now.
>
> MAJOR BENEFIT(s):
> + New functions can be easy localized (critically important while introduce
> new peoples into project).
> + Security: glue class do not see anything protected.
> + Light binding new functions with existing classes.
> + Number of used classes reduction.
> + Allow to assign methods and functions(static methods) to arrays, classes,
> interfaces, …
> + It's proof against same method occurs in class and delegator as well like
> in two delegators.
> + Allow to link gained(.jar) logic with new one, witch is impossible before
> final developer implements his classes.
> + Allow to project compact interfaces and do not worry about additional
> logic.
>
>
> MAJOR DISADVANTAGE:
> Do not know any ;) sorry.
>
> ALTERNATIVES:
> Utils classes, more work on project, duplicated code...
>
>
> EXAMPLES
>
> SIMPLE EXAMPLE:
>
>
> Now time:
> public class base {
>
>   public static <T> T[] flatten(T[][] this) {
>     int length = 0;
>     for (T[] subArray : this) {
>       length += subArray.length;
>     }
>     T[] ret = (T[])
> Array.newInstance(this.getClass().getComponentType().getComponentType(),
> length);
>     int pos = 0;
>     for (T[] subArray : this) {
>       System.arraycopy(subArray, 0, ret, pos, subArray.length);
>       pos += subArray.length;
>     }
>     return ret;
>   }
>
> }
> Now time(usage):
>   public static void main(String[] args) {
>     Integer[][] array = new Integer[][] { { 1, 2, 3, 4 }, { 5, 6, 7 }, {}, {
> 9, 0 } };
>     System.out.println(Arrays.toString(base.flatten(array)));
>   }
>
> Glue:
> public class base<T> glue( T[][] ) {
>
>   public glue T[] flatten( this) {
>     int length = 0;
>     for (T[] subArray : this) {
>       length += subArray.length;
>     }
>     T[] ret = (T[])
> Array.newInstance(this.getClass().getComponentType().getComponentType(),
> length);
>     int pos = 0;
>     for (T[] subArray : this) {
>       System.arraycopy(subArray, 0, ret, pos, subArray.length);
>       pos += subArray.length;
>     }
>     return ret;
>   }
>
> }
> Glue(usage):
>   public static void main(String[] args) {
>     Integer[][] array = new Integer[][] { { 1, 2, 3, 4 }, { 5, 6, 7 }, {}, {
> 9, 0 } };
>     System.out.println(array..flatten()..toString());
>   }
>
> ADVANCED EXAMPLE:
> Now time:
> public class base {
>
>   public static <T> int addAll( ArrayList<T> this, Iterator<? extends T>
> iterator) {
>     int added = 0;
>     while (iterator.hasNext()) {
>       added += this.add(iterator.next()) ? 1 : 0;
>     }
>     return added;
>   }
>
>   public static <T, E extends T> int addAll(ArrayList<T> this, E[] elements)
> {
>     int added = 0;
>     for (T t : elements) {
>        added += this.add(t) ? 1 : 0;
>     }
>     return added;
>   }
>
> }
> Now time(usage):
>   public static void main(String[] args) {
>     Integer[] add = new Integer[] { 1, 2, 34, 2, 5, };
>     ArrayList<Integer> arrayList = new ArrayList<Integer>();
>     ArrayList<Integer> finall = new ArrayList<Integer>();
>
>     base.addAll(arrayList, add);
>     base.addAll(finall, add);
>     base.addAll(finall,arrayList.iterator());
>
>     System.out.println(finall);
>   }
>
> Glue:
> public class base<T> glue( ArrayList<T> ){
>
>   public glue int addAll( this, Iterator<? extends T> iterator) {
>     int added = 0;
>     while (iterator.hasNext()) {
>       added += this.add(iterator.next()) ? 1 : 0;
>     }
>     return added;
>   }
>
>   public glue <E extends T> int addAll( this, E[] elements) {
>     int added = 0;
>     for (T t : elements) {
>       added += this.add(t) ? 1 : 0;
>     }
>     return added;
>   }
>
> }
> Glue(usage):
>   public static void main(String[] args) {
>     Integer[] add = new Integer[] { 1, 2, 34, 2, 5, };
>     ArrayList<Integer> arrayList = new ArrayList<Integer>();
>     ArrayList<Integer> finall = new ArrayList<Integer>();
>
>     arrayList..addAll(add);
>     finall..addAll(add);
>     finall..addAll(arrayList.iterator());
>
>     System.out.println(finall);
>   }
>
> Glue second:
> public class base glue( Date )
> {
>   private static final SimpleDateFormat sdf = new
> SimpleDateFormat("yyyy.MM.dd");
>
>   public glue String format( this ) {
>     synchronized (sdf) {
>       return sdf.format(this);
>     }
>   }
>
>   private static final Date applicationStart = new Date();
>
>   public static glue Date applicationStart() {
>     return applicationStart;
>   }
> }
> Glue second(usage):
>   public static void main(String[] args) {
>     System.out.println(Date..applicationStart()..format());
>   }
> DETAILS
>
> SPECIFICATION:
> JLS 8.8:
> ClassDeclaration:
>   NormalClassDeclaration
>   GlueClassDeclaration
>   EnumDeclaration
>
> GlueClassDeclaration
>   ClassModifiers_opt class Identifier TypeParameters_opt glue (
> GlueFormalParameter ) GlueClassBody
>
> GlueFormalParameter
>   VariableModifiers Type
>
> GlueClassBody:
>   { GlueClassBodyDeclarations_opt }
>
> GlueClassBodyDeclarations:
>   GlueClassBodyDeclaration
>   GlueClassBodyDeclarations GlueClassBodyDeclaration
>
> GlueClassBodyDeclaration:
>   GlueClassMemberDeclaration
>   StaticInitializer
>
> GlueClassMemberDeclaration:
>   FieldDeclaration
>   StaticMethodDeclaration
>   GlueMethodDeclaration
>   StaticClassDeclaration
>   InterfaceDeclaration
>   ;
>
> GlueMethodDeclaration:
>   GlueMethodHeader MethodBody
>
> GlueMethodHeader:
>   MethodModifiers_opt glue TypeParameters*opt ResultType
> GlueMethodDeclarator Throwsopt
>
> GlueMethodDeclarator:
>   Identifier ( this,*opt FormalParameterListopt )
>
> *opt: 'this' occurs always and only if glue method is not static.
>
> TypeParameters from GlueClassDeclaration are always visible for
> TypeParameters in GlueMethodHeader (even if method is static).
>
>
> 15.12 Method Invocation Expressions:
>
> GlueMethodInvocation:<br />
>   Primary .. NonWildTypeArguments*_opt TypeName_opt GlueMethodIdentifier (
> ArgumentList_opt )<br />
>   super .. NonWildTypeArguments*_opt GlueMethodIdentifier ( ArgumentList_opt
> )<br />
>   ClassName . super .. NonWildTypeArguments*_opt GlueMethodIdentifier (
> ArgumentList_opt )<br />
>   TypeName .. NonWildTypeArguments* GlueMethodIdentifier ( ArgumentList_opt
> )<br /><br />
>
> NonWildTypeArguments* suit TypeParameters in GlueMethodHeader.<br /><br />
>
>
>
>
>
>
>
> COMPILATION:
> If object (except null) is valid for GlueFormalParameter then glue-method
> can be called for this object.
> If type is compatible with GlueFormalParameter then static glue-method can
> be called for this type.
> For non static methods glued-object is passed as first 'this' parameter.
> Compiled method signature contains TypeParameters from GlueClassDeclaration
> (at start), and it's always static.
>
>
> TESTING:
> Like simple static methods.
>
> LIBRARY SUPPORT:
> No.
>
> REFLECTIVE APIS:
> No.
>
> OTHER CHANGES:
> No.
>
> MIGRATION:
> None.
>
> COMPATIBILITY
> New jars are fully compatible. Code is only backward compatible.
>
> REFERENCES
>
> Glue classes proposal 0.9 :
> http://lasu2string.blogspot.com/2009/03/glue-classes-proposal-09.html
>
> Bug: Extension of 'Interface' definition to include class (static) methods:
> http://bugs.sun.com/view_bug.do?bug_id=4093687
>
>
>
>   




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